Question

I read that photosynthesis is an anabolic pathway and respiration is catabolic pathway , but my doubt is, even in photosynthesis, in light phase the energy I mean ATP is released. then why we consider photosynthesis as an anabolic pathway?

Answer 1

Photosynthesis is an anabolic process.
This is because in anabolism, complex molecules like proteins are created and synthesized from smaller, less complex molecules, such as amino acids.
Anabolic Reactions are energy requiring reactions.

Energy is released but is stored for future use and thus photosynthesis is an overall anabolic process.
The energy released by the breakdown of the water molecule is used to create ATP from ADP. Some of the created ATP (with its stored, potential energy)
is used in the second stage of photosynthesis. This is called the Calvin Cycle.

In this cycle the ATP releases energy which acts on Carbon Dioxide (CO₂) and the electron receptor molecule mentioned above to create sugar molecules containing three Carbons.

Some of these sugars enter the cytoplasm of the plant cell. They are subsequently converted to glucose, fats, and amino acids. These then serve various functions within the cell and as a source of stored energy for the plant. Animals eat the plants and also make use of this stored energy.